Barrel

A Barrel is an item used to store and transport fluids when pipes are unavailable, impractical, or undesirable. Barrels allow individual units of many in-game fluids to be moved by belts, trains, cars, tanks, logistic robots, or carried in a player inventory. Filled barrels are produced and consumed by dedicated fill and empty processes in assembling machines; the item exists primarily as a convenient, mobile container for liquids such as Crude oil, Heavy oil, Light oil, Lubricant, Petroleum gas, Sulfuric acid, Water, Fluoroketone (Hot), and Fluoroketone (Cold).

Empty barrels can be crafted from steel plate once the Fluid handling technology is researched. When a filled barrel is emptied in an assembling machine, the process returns an Empty barrel along with the contained fluid to the machine’s output. Conversely, creating a filled barrel consumes an Empty barrel plus the required fluid using a Fill barrel recipe in Assembling machine 2 or Assembling machine 3. Filled barrels themselves cannot be directly crafted by standard item recipes; they must be produced by the fluid-specific Fill barrel processes. Likewise, Empty barrel recipes produce the base empty container used by those processes.

The barrel workflow is symmetrical: a Fill barrel process takes an Empty barrel and a unit of the chosen fluid and outputs a corresponding filled barrel; an Emptying process in an assembling machine takes a filled barrel and outputs the fluid plus an Empty barrel. All filling and emptying operations are performed in assembling machines (Assembling machine 2 or 3). Barrel filling and emptying recipes do not accept productivity modules or quality modules.

Barrels are particularly useful in situations where pipe networks are impossible or inefficient. They are commonly used to:

• Move oil or other fluids from remote resource patches to the main base when building long pipe runs is undesirable.
• Transport fluids between planets or across gaps in space platforms where pipes cannot be placed.
• Supply small, intermittent quantities of a fluid to bootstrap specific production chains (for example, using a unit of Heavy oil to kickstart coal liquefaction, or transporting a single unit of ore-derived product needed to trigger Uranium processing research).
• Allow belt- or wagon-based logistics for fluids, or to hand-carry fluids in emergency or exploratory operations.

Practical handling notes:

• Use Assembling machine 2 or 3 for both filling and emptying operations.
• Long-handed inserters can transfer barrels across tiles that cannot be bridged by pipes, such as over lava or platform gaps.
• Filled barrels stack and move like regular items, enabling integration with standard belt and train systems as well as logistic robots.
• Remember that the barrel filling/emptying recipes cannot use productivity or quality modules, so plan throughput and machine placement accordingly.